Advanced nucleic acid sequencing technology was introduced in the 1980's as an improved technology in the study of molecular biology. Among others, U.S. Pat. Nos. 5,171,534, 4,811,218 and 5,192,412 disclose the basic principles and some preferred embodiments of electrophoresis apparatus and/or systems.
In U.S. Pat. No. 5,171,534, a column type gel is disclosed to perform the electrophoresis process. In the disclosed process, chromophores or fluorophores are used to tag the DNA fragments produced by the sequencing chemistry and permit the detection and characterization of the fragments as they are resolved by electrophoresis through the gel. The detection disclosed employs an absorption or fluorescent photometer capable of monitoring the tagged bands as they are moving through the gel.
In U.S. Pat. No. 4,811,218, a flat panel type gel is disclosed to perform the electrophoresis process of many samples at the same time. The disclosed system includes an optical system and a translational stage for mounting the optical system and for moving the optical system in a direction parallel to the planar array of electrophoresis lanes in order to move a collection element to receive radiation from different lanes, one lane at a time.
The above two types of electrophoresis apparatus tag four different fluorescence molecular to four DNA fragments terminating with A,T,C, and G respectively. The technology disclosed makes the electrophoresis process possible by using a single electrophoresis lane instead of the conventional four lanes. Furthermore, these electrophoresis apparatus avoid the need for providing multiple injections for samples with long DNA molecule.
In U.S. Pat. No. 5,192,412, lengthwise grooves are formed in one surface of a plane plate serving as a capillary electrophoresis path. A widthwise groove intersecting the lengthwise grooves is provided for the passage of a light beam.
However, even with the technology of the state of art, the electrophoresis process for large number of samples is still time consuming.